High speed baking in novel toasting apparatus

ABSTRACT

An electric baking oven includes an open mesh vertically oriented baking basket to hold food while the food is baked in air by a programmed combination of radiant and convective and conductive energy transfer. An electrical programming control controls the energy from vertically oriented toaster heating elements located juxtaposed to the large vertical faces of the basket and from at least one elongated heating member located below the vertical baking basket with the axis of the elongated heating member oriented nominally horizontal and parallel to the longer horizontal axis of the vertically oriented baking basket.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a division of application Ser. No.09/917,996, filed Jul. 30, 2001, which is a continuation in part ofapplication Ser. No. 09/569,841, filed May 12, 2000, now U.S. Pat. No.6,267,044, which is based on provisional application, Ser. No.60/133,914, filed May 13, 1999.

BACKGROUND OF INVENTION

[0002] Parent U.S. Pat. No. 6,267,044 describes a toaster which containsheating elements optimally designed and positioned for toasting andprovides the means to preheat the toasting elements to optimal thermalconditions for toasting before introducing the bread or other materialto be toasted into the toasting environment. The novel toaster designdisclosed in that patent includes also added means to create the optimalconditions for baking, warming, defrosting or a combination thereof. Thedesign geometry, size and thermal environment of the relativelyubiquitous conventional toasters have not proven satisfactory forquality baking, defrosting or warming. By contrast this toaster willperform these functions faster and better than conventional baking ovenscommon to virtually all kitchens.

[0003] Conventional baking ovens that have been used for centuries aredesigned with horizontal shelves to cook food in horizontal containersthat are slowly raised to elevated temperatures by heated air. Food inthose containers is heated primarily by contact with the hot horizontalcontainer or by contact with adjacent food in turn heated by contactwith the container.

[0004] In more recent times motor driven fans have been introduced inovens to circulate the air around the containers and over the top offoods in horizontal containers or horizontal shelves. Large electricalheaters have been added on the ceiling, floors and side walls of ovensto heat the air more rapidly. Horizontal shelves are provideduniversally as the means to hold food containers and in some cases toposition bread or other foods horizontally in close proximity to ahorizontal mounted heater that will toast or broil one side at a time.The efficiency of the toasting operations is very poor taking manyminutes to toast—leaving a dry relatively unappetizing product. Largeovens of that sort take 10 or more minutes just to reach bakingtemperatures and substantial time to complete the baking because ofinefficient heat transfer to the food. No provision is made in suchovens to insure intimate and direct contact with all surfaces of thefood when that food is particulate or simultaneously with both sides ofthe food if the food is planer such as steaks, patties, and waffles. Anexception to that is the rotisserie that secures larger foods on skewersand rotates them before the heated air, flames, or heated elements.

SUMMARY OF INVENTION

[0005] The present invention is directed to techniques for optimalbaking cycles in the unique toaster of parent U.S. Pat. No. 6,267,044.

[0006] This invention describes the means and mechanism to holdparticulate food within a toaster so that there is direct and intimatecontact between heated air and virtually all the foods surface area toinsure rapid and uniform heating of the food by naturally convectivetransfer from hot air at baking temperatures in combination withprogrammed temperature radiant energy from toasting elements and atleast one auxiliary heater operating at optimum temperatures which aredifferent from those that must be employed in an optimal toasting cycle.This programmed combination of heating by the hot air and radiationprovides optimum baking rates without overheating the exposed surfacesof the food in such a manner as to create excessive or burning of thefood surface. By this new methodology and by the close proximity of theheating system and the toasting elements it is possible to optimize thebaking conditions for the effective baking of hundreds of uncooked or“precooked but not browned” foods available for quick bake-and-servedishes. Unlike conventional ovens and toasters which cook slowly andunevenly, the means disclosed here bakes rapidly and uniformlysimultaneously on virtually all surfaces of particulate foods creatingtasty uniform temperature foods as a result.

[0007] Many ovens and so called toaster-ovens can be used for toastingbut the toasted food lies flat and must be turned over to complete thetoasting or to achieve relatively uniform toasting on each side. Thoseheater elements are not optimized for toasting. In the baking mode inconventional ovens there is little motion of the air over or through thefood, rather the air is relatively quiescent. Convection ovens with fansgenerate a general air flow within the oven but these are not designedto circulate air through a bed of particulate food—such as frozen frenchfries. Conventional toasters are used today in an attempt to “cook” manyof the frozen “precooked but not browned” foods by simply repeating thetoasting cycle several times. The results are very disappointingcreating overcooked and undercooked areas—sometimes burnt before gettingsufficiently warm on the interior. Good baking requires less intenseheat in order that the interior can be warmed sufficiently before thesurface is overheated or burnt.

[0008] No provision is made in such ovens for vertical open baskets tohold the food and to allow air to pass through a bed of particulatefood—such as frozen french fries.

[0009] There have been attempts to offer toasters that combine thetoasting and baking functions such as U.S. Pat. No. 2,862,441 by W. A.Schmall (Dec. 2, 1958) assigned to General Electric. This describes acombination unit which uses movable mirrors to redirect radiant energyupward for toasting or downward to a separate baking compartment. Thatbaking function can not be particularly effective since the heat wasapplied only by the mirrors to one side of the food.

[0010] In contrast to prior art the subject baking appliance is designedfirst as an optimal toaster. Baking is accomplished in the same spacewith the use of an auxiliary air heater mounted below the baking spaceand with the use of sophisticated electrical and electronic control ofthe toasting elements to equalize air temperatures and to generatenatural convection currents of the heated air through and aroundvertically configured open mesh basket that contains the particulatefood. The relative amounts of heat provided by the toasting elements andby the auxiliary air heater are electronically controlled to optimizethe baking rate while avoiding excessively localized heating of the foodsurface by either the localized air temperature or the radiation fromtoasting elements. The toasting elements are segmented so that they canbe heated individually or together and thus temperature is controlled soas to optimize the air temperature along the vertical face of thevertical open mesh basket which holds the food to be baked.

[0011] U.S. Pat. No. 6,267,044, the details of which are incorporatedherein by reference thereto, describes many of the novel aspects of thisnew batch toaster in particular means for retaining the food to betoasted remote from the toasting zone until the thermal conditions inthe toasting zone are optimal for toasting. By that means the bread orother food to be toasted is when entered into the toasting zone, toastedrapidly avoiding unnecessary drying of the food that would otherwisetake place before the ambient thermal conditions are optimal fortoasting of the food surface. Consequently the toasted food loses lessinternal water and can be crisp on its exterior surface while retainingmore of its internal moisture. The food to be toasted is placed on acarrier of some sort and transported either manually or automaticallyinto the toasting zone when that zone is thermally optimal for toasting.

[0012] For toasting to occur rapidly, and thus reduce the loss ofmoisture from the food, it is best that heat transfer be largely byradiation and less by a combination of hot air conduction and convectionwhere heat transfer is inherently slower limited by the thin layer ofair in the boundary layer adjacent the food surface. Heat transferthrough such boundary layers is inherently slower while radiation canpass literally at the speed of light uninhibited from the radiant sourceonto the food surface. When toasting this speed is advantageous. Whenbaking one has to monitor and control carefully the amount of radiantenergy so as to avoid burning the surface of the food before theinterior is adequately baked. For the interior of the food to be bakedsufficiently, heat must be first transferred to the surface of the food,whence heat must travel by conduction to the middle of the foodthickness. The latter takes time because the thermal conductivity offood is poor and the amount of heat transferred is driven only by theelevated surface temperature of the food. The higher the surfacetemperature the better up to the point where the surface is overheatedand begins to burn or overcook. Consequently the surface temperaturemust be carefully controlled and limited to avoid burning but it must behot enough to drive effectively the heat below the food surface where itis needed to evaporate excess water and to dehydrate and crosslink thefood proteins or break chemical bonds.

[0013] Toasting, a surface phenomenon, can be forced to occur rapidly.By contrast baking rates are limited by the slow transfer of heatthrough the full thickness of foods. Baking cannot be rushed withoutdanger of burning the surface. This is why toasters are notoriously poorfor baking. The intensity of toasting elements must be moderated if theyare used during extended baking to assist in heating the surface offoods. Radiation from toasting elements will not shine onto all foodsurfaces within a bed of particulate food. Shadowing effects limit theeffectiveness of direct radiation. Heat for the surface of interiorparticulate surfaces can be well provided by convective and conductivetransfer from hot air circulating around and between the particulatefood.

[0014] From the above it is clear that a thermal environment ideal fortoasting is not suitable for quality baking. Similarly the environmentoptimal for baking is totally unsatisfactory for toasting. What thisinventor has discovered is that it is possible to bake efficiently andrapidly in the toasting space by using segmented electrical toastingelements operating at reduced temperature as auxiliary heaters tosupplement a remote efficient heating means to elevate the airtemperature within the enclosure and to generate natural convectioncurrent around and through a bed of particulate food adjacent to thetoasting elements. The baking process can be optimized by programmingindependently the temperature of the segmented toasting elements and theremote heating means throughout the baking cycle. In the relativelyshort initial heat-up phase of the baking cycle (approximately 1 ½minutes) both the upper and lower toasting segments are powered to anelevated temperature equal to or slightly lower than their temperaturewhen toasting. This provides an initial burst of radiant and convectiveheat transfer that elevates the temperature of the food surface andhastens the overall temperature rise of the enclosed air, the oven wallsand the baking basket. In the initial phase the remote heater alsooperates at or close to full power to hasten the heat-up process.Temperature within the baking space is monitored to determine when ithas reached the desired baking temperature. After that time usually lessthan 2 minutes, the toaster elements are operated at reduced temperatureand the power applied to the remote heater and to the toaster element iscontrolled to maintain the oven temperature at the desired temperature.

[0015] Any of a variety of electrical control means can be used toprogram during each portion of the baking cycle the appropriate amountof power to the toasting elements and to the remote heating means. Asolid state relay controlled by an oven temperature sensing means provedparticularly effective for controlling power to the various heatingelements.

[0016] This inventor has found that the uniformity and speed of bakingof particulate foods is enhanced significantly if the food is held in anelongated vertically oriented mesh basket of cross section sufficientlysmall that heated air can readily pass by naturally convective meansthrough the basket thus contacting efficiently the surfaces of theparticulate food held therein. Using a specific arrangement of heatingelements and by employing a vertical basket of approximately 1 ¾ to 3inch thickness (between the large vertical mesh faces) naturalconvection of the heated air passes rapidly through such a basketinsuring that the particulate food is uniformly heated and bakedthroughout the basket.

[0017] A vertical configuration of the baking basket is optimal and itis consistent with the toasting geometry optimal for toasting asdescribed herein and in parent U.S. Pat. No. 6,267,044. The elongatedvertical orientation of the baking basket allows toasting heatingelements of similar orientation to be used effectively to aid in theheating process and to apply heat uniformly to the face of the elongatedvertical baking basket.

[0018] By using an elongated relatively high power heater (approximately600-1000 watts) under the basket, air heated by this means risesnaturally by virtue of its reduced density along the vertical faces ofthe mesh basket. By physically offsetting the heater slightly, on theorder of a quarter inch or so from the long center line of the bakingbasket it was found that there is greater air flow up one side of thebasket creating enough pressure difference between the faces of thebasket to force a significant fraction of the hot air through thethickness of the mesh and across the surfaces of the cooler particulatefood. It was found convenient to use a high temperature elongated sourcesuch as a cal-rod or a quartz-enclosed conventional hot wire heater.Because of the high temperature required for efficient heat transfer toair by such a source it may be hot enough to radiate significant energy.In that event the bottom of the mesh basket is best shielded from thedirect radiation emitted by the heating source. One way to prevent thedirect radiation from shining on the food basket is to locate thatsource in a relatively open but roofed compartment below the foodbasket. The mesh baking basket can be supported by, but spaced above anintegral solid metal base. The bottom of the open mesh basket shouldoptimally be positioned at least ⅜″ above any such base. By these meanshot air can ascend up through the mesh bottom of the basket. Either themetal base or the roof of the heater compartment will shield the foodfrom direct radiation from the lower heater.

[0019] More than one air heater can be used below the baking basket andtheir positioning can be arranged to provide greater air flow up oneface of the basket and then pass the other to create a pressuredifference across the faces of the basket and flow through the basket.

[0020] The elongated vertical configuration for the baking basket hasproven ideal because it conforms directly with the planar geometry ofthe toasting heater boxes and it allows air heated from below to passuniformly upward along and across the entire large faces of the bakingbasket and through the particulate food. The advantages of thisarrangement can be readily visualized in comparison to the use ofconventional horizontal pans, horizontal trays or open mesh shelving.None of these conventional baking configurations offer the possibilitysimultaneously for the symmetry and proximity of auxiliary planarheaters such as the toaster elements adjacent both major faces of thebasket as described here nor do they offer opportunity forsimultaneously creating uniform naturally convective air currents alongboth sides of the food basket and through its food bed.

[0021] The effectiveness of the natural convective hot air currentsthrough the cool food was demonstrated by detailed temperaturemeasurements of the food temperature and the air temperature adjacent tothe baking basket. It was observed when the long axis of the lowerheater was offset ¼ inch or so from the lower center line of the basket,convective air currents through the food increased sufficiently toequalize the air temperature adjacent to the food to that of the risingmain air stream. When the lower heater was centered the air temperatureadjacent the cool food dropped below the temperature of the air aboveand below the food level reflecting much less convective circulationthrough the food. When the heater was set off center the food cooked(reached ultimate temperature faster) and it was cooked more uniformlythroughout the food bed.

[0022] This unique toaster and baker is designed to optimize separatelyits performance for each of these two functions. None of the known batchtoasters preheat the toasting element and toasting environments beforetoasting to create the crispy yet moist texture. None of the known batchtoasters are effective for baking. Toaster ovens are available thatoffer the ability to either toast or bake. They do not offer means tooptimize the toasting environment before introducing the bread. Neitherdo they offer optimal means to bake in a vertical basket by combiningthe heating advantages offered by precise and programmed control ofadjacent planer toasting elements and a remote heater to generateefficient heated air convection currents past and through a bed ofparticulate food.

THE DRAWINGS

[0023]FIG. 1 is a perspective view of a baking oven in accordance withthis invention;

[0024] FIGS. 2-3 are cross-sectional views in elevation showing thebaking element of FIG. 1 in different phases of operation;

[0025]FIG. 4 is an enlarged elevational view showing the toasting basketof FIGS. 1-3;

[0026] FIGS. 5-6 are perspective views showing the toasting basket ofFIG. 4 in its opened and closed positions, respectively;

[0027]FIG. 7 is a longitudinal cross-sectional view showing the toastingbasket of FIGS. 1-6 lowered into the toasting zone;

[0028]FIG. 8 is a view similar to FIG. 7 showing the toasting basket inits opened condition;

[0029]FIG. 8A is a cross-sectional view taken through FIG. 8 along theline 8A-8A;

[0030] FIGS. 9-10 are views similar to FIG. 2-3 showing the oven usedfor baking in accordance with this invention;

[0031] FIGS. 11-12 are perspective views of a baking basket in itsclosed and opened conditions, respectively; and

[0032]FIG. 13 is an enlarged cross-sectional view in elevation of adrive mechanism which may be used for the oven in accordance with thisinvention.

DETAILED DESCRIPTION

[0033] The unique design of this toaster and baker is based upon thatdescribed in parent U.S. Pat. No. 6,267,044, the details of which areincorporated herein by reference thereto. The baking basket and thebaking function are described in the following

[0034]FIG. 1 is an overall view of this new toaster/baker 10. Anelectronic control pad 2 is provided so that the user can select eithertoast or bake. If toasting there is a choice of the toasting cycleeither; (a) to preheat the toasting chamber before toasting or; (b) tointroduce the bread or other food before heat-up. The first sequencecreates a toast with crisp exterior and a moist interior, the secondcreates a drier toast crunchier throughout its thickness. There arecontrols on panel 2 also for selection of the baking temperature andtime of bake.

[0035] The toaster/baker 10 outer shell 12, FIG. 2 is generally made ofplastic spaced an appropriate distance outside an inner metal shell 12Athat encloses the heated oven. Air intake openings 4 along the bottom ofthe toaster/baker 10 allow cool room air to enter and rise in the space5, between the inner shell 12A and the outer shell 12, as shown in FIG.2. The air removes heat from that space 5, rises as it is heated by thehot inner shell 12A and exits vents 3 located at the top of the toaster.The vents 3 can be located either as shown in FIG. 1 or on the exteriorside of the opening 16 in top wall 14.

[0036] The same appliance may be converted to and from a toaster and abaking oven in accordance with the electrical controls selected and withthe type of basket used for the food. Food to be toasted is inserted ina toasting basket 18 shown in FIGS. 2-6. Food items to be baked areinserted in baking basket 7, FIGS. 9-12.

[0037] For toasting, the toasting basket 18, FIGS. 5 and 6, is insertedinto the large toaster opening 16, FIG. 3 in an unheated waiting zoneabove toasting zone 26. The bread 25 or other food to be toasted isreadily inserted in the basket 18 on tray 20, FIG. 5. The hinged rails22 and 24 which are pivoted at their lower ends to mounting structure28, are normally held in the open position by springs 30 that pull theserails outward as shown in FIGS. 4 and 5. When the toasting basket islowered into the toasting zone 26 the rails are in the open position.When the toasting basket is lowered the toasting cages 38, FIGS. 2 and3, located inside the toasting zone 26 advance toward the bread or otherfood in the toasting basket, the toasting cage engages the hinged railsand by means of spring rod 35 presses them lightly against the food tomove the food to the center line of the basket and to hold it uprightduring the toasting cycle. As shown in FIGS. 4-6 stop member 29 limitsthe outward movement of the basket rails.

[0038] In the toasting mode food is placed in the toasting basket 18where in one option it is held in the waiting zone until the temperaturein the toasting zone 26 is optimal. The basket is then lowered by meansof motor 48 of FIG. 7 into the toasting zone. As the basket is loweredthe contact arms 32, FIGS. 2 and 3, attached to the toasting basketcontacts the actuating arm 34 which is rigidly fastened to spring rod35. Spring rod 35 then moves the toasting heater cages 38, FIGS. 2, 3and 7 away from its location near wall 12A and into contact with thehinged rails 22 and 24 of the toasting basket pressing the rails intocontact with the bread or other food to be toasted. Retraction springs42 attached to the cages 38 serve to pull the toasting heater cages backand away from the toasting basket when the toasting cycle is completed.Cages 38 may move back and forth between the positions shown in FIGS. 2and 3 in any suitable manner such as by the provision of pins 37 mountedto the lower end of each support arm 36,36 and mounted to partitions59,59 as shown in FIGS. 8 and 8A. Parallel support arms 36, FIGS. 2 and3, serve to keep the toaster heater cages 38 nominally vertical andparallel to the toasting basket as the cages are moved forward orretracted. It is desirable during toasting that the hot wire elements40A and 40B in the toaster heater cage be operated at a high luminoustemperature—about 1600° F. to toast as rapidly as possible, withoutburning, in order to toast with minimal loss of water from the bread orother food. By this means the toasting cycle can be completed in about45 seconds to 1 minute. The other heating element 44 is an elongatedheating member located below the toasting basket that is not used duringthe toasting cycle. As the toasting basket returns the toasted food tothe top of the toaster, the bottom of the toasting basket seals off thetoasting chamber so that on the next cycle the toasting zone can bereheated without heating significantly the bread or other food held inthe toasting basket while the toasting zone is being reheated.

[0039] Either the toasting basket 18 or the baking basket 7 can bemounted on the carriage support arm 21, FIGS. 2, 3 and 7 which is raisedand lowered by the motor 48. The upper surface of the carriage supportarm 21 is U shaped to hold securely either of the baskets 18 or 7. Thesupport arm is cantilevered off of support bracket 56, FIG. 7 which inturn is supported on the carriage support rod 60. Two roller bearings 58attached to the bracket 56 support the weight of the carriage supportarm and either food basket with its load of food. The far end ofcarriage support arm 21 rides in an enclosed guide, such as slot 63, atthe end of the toasting compartment to maintain horizontal alignment ofthe carriage support arm. The enclosed slot 63 prevents loss of heatfrom the oven environment. The carriage support 21 is raised or loweredby the attached threaded nut 54 that is driven up or down the threadeddrive screw 52, (supported by end bearing 61) by the gear train 50driven by the motor 48. See FIGS. 7, 8 and 13. Partition 59 isolates themotor drive section thermally, from the heated toaster/bakingenvironment. As needed, thermal insulation can be added to the partitionwall to further reduce heating of the motor and drive elements. Thecarriage support arm extends from the motor compartment through a narrowelongated slot in the partition wall 59. Heat transfer through that slotcan be minimized during the heating cycle (when the baskets are lowered)by incorporating solid wall end plates 64 as shown on the end of thebaking basket, FIGS. 11 and 12.

[0040] The baking basket assembly 7 is detailed in FIGS. 11 and 12.Assembly 7 is shown partially lowered into the baking zone, FIG. 10, andfully inserted in FIG. 9. This assembly has an attached solid bottomtray 8 that serves to catch and contain any grease or crumbs that willfall from particulate or other food placed in the mesh basket 6. Thisbasket has two vertical mesh side panels 6A that are hinged 9 so thatthey can lie flat, FIG. 12, when removed from the toaster to assist easyremoval of food after cooking. The basket has a mesh bottom 6B spaced ½inch or so above the bottom tray 8. This spacing is critical to allownatural convection of the heated air rising from the lower chamber tocirculate up through the mesh bottom and through the food in that area.The mesh construction of the large vertical faces 6A allows very freeconvective hot air circulation through those faces and the food. It isimportant of course that the width of the basket, that is the distancebetween the large vertical faces, does not become excessive and as aconsequence restrict the convective flow rate across the food bed. Thelength of the basket is not critical other than it must correspondroughly to the length of the toasting elements in order that they can beeffective in transferring heat along the entire length of the basket.The height of the basket likewise should not extend significantly higherthan the toasting heater cage for most effective heating by the toastingheater elements. The practical thickness of the mesh basket for foodssuch as french fries is less than 3 inches. For looser packed foods suchas onion rings a thicker basket could be used.

[0041] As stated earlier the vertical configuration of the basket iscritical in order to make effective use of the vertical planerconfiguration of the toasting heaters and to make effective use of anauxiliary heater to induce significant natural convection currentsthrough the food bed. This is an optimal combination which avoids thenecessity to add a circulating fan to force greater airflow in order tobake uniformly.

[0042] The baking basket assembly shown in FIGS. 11 and 12 has closedend walls 64 each terminated at the top with plastic handles 66 thatremain outside the baking zone and hence remain sufficiently cool toallow the basket assembly to be readily removed from the toaster.

[0043] The vertical mesh sides of the basket when raised to the verticalposition are held in place by retaining clips 11 attached to end walls64. Along the top of the basket, FIG. 11, are two hinged planar coverlids 65 which are automatically closed as the basket assembly descendsinto the toaster. Their closure is effected by the shape of the twoclosure latches 62 attached to the lid 65 as they pass shoulder 14 wherethe outer toaster cover 12 meets the vertical face 15 (FIG. 1) definingthe top opening slot of the toaster. The two planar cover lids 65 do notcompletely close off the top of the basket as they drop, rather theyleave an air gap slot about ¼ inch wide. This air gap allows some hotair to escape out the top of the baking zone when baking. The width andshape of that slot is optimized to insure more uniform temperaturethroughout the baking basket, to assist the upward flow of hot airaround and through the food and to avoid creating an excessively hotlayer of air just under the lids. A delicate balance of the power to theheating elements and the amount of air flow up and out of the toasterwhen baking is important to the quality and uniformity of the baking.

[0044] Small flanges 67 extending at an angle from the hinged bakingbasket lids 65 serve to minimize leakage of hot air from the baking zonealong the extended top corners of the baking basket when the bakingbasket has been lowered into baking position. These small flanges 67seal against structural members 13 part of the toaster structure.

[0045]FIG. 10 shows the baking basket 7 partially inserted into thetoaster/baker and FIG. 9 shows the basket 7 fully inserted. The basketis lowered into place by the motor driven carriage 21. The base tray 8of the baking basket fits within and is held by the recess of thecarriage 21. The basket is positioned vertically by virtue of the closefit of basket end plates 64 with the walls of the toaster/baker topopening 16.

[0046] The motor driven carriage arm 21 extends through a slot inpartition 59, FIG. 7, that encloses the toaster/baking zone and servesas a heat barrier for the motor compartment. The far end of carriage arm21 extends into and is guided by enclosed slot 63. As the baking basket7 is lowered into the baking zone its end plate 64 slides in closecontact with partition 59 to seal off most of the air flow through theslot in partition 59 through which the carriage arm extends.

[0047] The baking heater 44, FIGS. 7-10 is located below the carriagearm 21 and under the food baskets. Heater 44 is also below horizontalshielding plate 68 that prevents direct radiant energy emitted by thelamp heater 44 from shining directly on the baking basket. It alsoshields the heater from any food particles that may fall from side ofthe food basket. On each side and slightly below that heater are crumbtrays 46 that can be constructed either as two separate units or joinedby a lower plate (not shown) so that they be removed together forcleaning.

[0048] In the baking mode the toasting heater cages remain in aretracted position in order to allow the air from heater 44 to passfreely between those heaters and the baking basket. The upper row ofheater wires 40A on the toasting boards and the lower row 40B are notpermanently connected together electrically and instead each row can beprogrammed to have full or partial line voltage across them or the rowscan be connected in series at full or partial line voltage. By thismeans these electrical toasting elements can be powered on full orpartially to establish the optimum amount of heat at their locationsopposite the large vertical faces of the baking basket to compliment theair heating means located below the horizontal partition plate 68. Thatplate 68 is just large enough to shield direct radiation to the food andto protect the lamp from falling debris or food particles, but not sowide as to restrict the flow of heated air passing up from the heater inthe space between the baking basket and the toaster heaters and passingconvectively through the food bed. Vertical walls 45 extend parallel toheater 44 on each side of the lower heater to confine and reinforce theair currents generated by the heater. These walls 45 extend from thebase of oven liner 12 to a height just short of the base of the movabletoasting cages 38.

[0049] The actuating arm 34, FIGS. 9 and 10, are actuated only by thetoasting basket. The baking basket does not contain the contact arms 32needed to move the actuating arms 34 which in turn tilts spring rod 35to move the toasting heater cages 38 in toward the toasting basket.

[0050] The typical baking cycle of this novel baking arrangement isshorter than that in convectional home ovens for two reasons.Importantly it takes much less time to heat up the baking zone. Furtherthe improved natural convection currents created by this combinedheating arrangement insures faster and more uniform heat transfer to thefood surface.

[0051] Because of these advantages, with this new baking arrangement thetotal time required for oven heat-up plus baking is slightly less thanthe time required just for baking in a conventional small toaster oven.The following example illustrates the advantage found in elapsed timewhen baking partially cooked but frozen foods in this new toaster/baker.

[0052] Frozen French Fries

[0053] Commercially available frozen french fries. These were precookedbut not browned by manufacturer before freezing. These were removedfrozen from commercial package and placed in oven promptly.

[0054] Conventional Toaster Oven—(Black & Decker TR0400, 1550 Watts)

[0055] Heat-up time—5 minutes to reach 450° F.

[0056] Baking time—30 minutes single layer—10 ounces French fries(single layer on metal tray)

[0057] Total time—35 minutes to bake thoroughly

[0058] Toaster/Baker (described above—20 ounces French fries; twice thequantity of french fries held by the Black & Decker toaster oven) (1480watts maximum) (basket size: 10.5 inches long, 5 inches high, 1.6 inchbetween vertical mesh faces)

[0059] Heat-up time—1 ½ minutes to reach 450° F.

[0060] Bake time—26 minutes

[0061] Total time—28 minutes to bake thoroughly

[0062] [It is evident that this new baking arrangement cooked in lesstime twice as many french fries as the conventional toaster/oven.]

[0063] The following baking sequence was used when baking with this newbaking apparatus:

[0064] Heat-up Period

[0065] Both upper and lower toaster elements 40A and 40B in bothtoasting cages were energized on full voltage for 1 ½ minutes. Thebottom baking heater (680 watts) was also on at full voltage for theheat-up period.

[0066] Baking Cycle

[0067] Following the heat-up cycle, the two lower toasting elements 40B(800 watts) connected in series electrically and the bottom bakingheater 44 were each powered at 120 Volts by a solid state relay, thatadjusted the amount of power as necessary to maintain temperatures atthe set point.

[0068] The amount of power delivered during the baking cycle to theseheaters subsequent to the heat-up period was automatically controlled bythe solid state relay in accordance with the electrical signal receivedfrom a conventional thermocouple junction located on a post attached toone toaster cage about ½″ in front of the toasting heater elements.During the baking cycle the amount of required power was reduced to onlya fraction of the initial power as the oven and food surface reached thepreset control bake temperature. The control temperature for baking wasin each test selected and set manually at the temperature recommended bythe packager of the frozen food product.

[0069] A saving of about 20% in total time compared to conventionalovens and toaster ovens was measured on a variety of frozen foodsincluding: onion rings, french toast nuggets (450° F.), hot pockets(350° F.), cheese toast (425° F.), croissant pockets (with sausage andcheese 350° F.) and hash brown potatoes (450°).

What is claimed is:
 1. A convertible electric baking oven for food itemsand a batch type toaster for sliced bread and the like comprising aheatable toasting zone, at least one heater in said toasting zone, amobile normally open toasting basket to hold the bread slice, an openmesh vertically oriented baking basket having large vertical faces tohold the food items, each of said toasting basket and said baking basketbeing selectively removably mounted in an unheated waiting zone remotefrom toasting zone, a transport mechanism to transfer said basket fromsaid waiting zone to said toasting zone, associated electrical andelectronic controls designed to activate said heater while restrainingmotion of said transport mechanism in said waiting zone remote from saidtoasting zone until the temperature of said heater and the thermalconditions in said toasting zone have reached designated heatingconditions and then direct said basket to enter and be held within saidtoasting zone until a heating cycle is complete.
 2. An oven according toclaim 1 wherein said heater includes segmented toasting elementsgenerally vertically arranged in said toasting zone.
 3. An ovenaccording to claim 1 wherein said heater include a heater located belowsaid baking basket when said baking basket is in said toasting zone, andsaid heater being offset from a longitudinal center line of said basket.4. An oven according to claim 3 wherein the bottom of said baking basketis shielded from direct radiation emitted by said heater.
 5. An ovenaccording to claim 4 wherein said bottom of said basket is shielded bylocating said heater in a relatively open but roofed compartment belowsaid baking basket.
 6. An oven according to claim 4 wherein said basketis supported by and spaced above a solid base to shield said bottom ofsaid baking basket.
 7. An oven according to claim 1 wherein said heaterincludes heating elements located at the sides of said toasting zone ina planar configuration facing said vertical faces of said baking basketwhen said baking basket is in said toasting zone.
 8. An oven accordingto claim 7 wherein said heater further includes an auxiliary heaterbelow said baking basket when said baking basket is in said toastingzone.
 9. An oven according to claim 1 wherein said baking basketincludes a solid bottom tray to catch and contain grease or crumbs thatmay fall from the food item.
 10. An oven according to claim 9 whereinsaid baking basket has a mesh bottom located above and spaced from saidbottom tray to allow natural convection of heated air rising tocirculate through said mesh bottom.
 11. An oven according to claim 9wherein said baking basket vertical faces are mesh side walls which arehinged to lie flat so as to facilitate removal of the food item aftercooking.
 12. An oven according to claim 11 wherein said baking basketincludes closed end walls having handles to facilitate the handling ofsaid baking basket.
 13. An oven according to claim 12 wherein saidbaking basket includes cover lids at the top of said basket, and saidcover lids being spaced from each other to create an air gap forallowing the escape of hot air.
 14. An oven according to claim 1 whereinsaid transport mechanism includes a carriage arm, each of said toastingbasket and said baking basket being selectively removably mounted onsaid carriage arm, said carriage arm being driven by a motor and drivestructure in a motor compartment, said carriage arm extending through aslot in a partition, and said partition forming a heat barrier for saidmotor compartment.
 15. A baking basket for holding items of food to becooked in a baking oven, said baking basket comprising a pair ofvertically disposed mesh side walls, said side walls beinginterconnected by a generally horizontal mesh bottom wall, a solid traymounted below and spaced from and supporting said bottom wall, each ofsaid mesh side walls being interconnected by a respective solid closedend wall, each of said end walls terminating at its top with a handle tofacilitate the holding of said basket, each of said end walls having amounting element for holding said side walls in an upright verticalposition generally parallel to each other, said side walls beingpivotally mounted at their lower ends to permit said side walls to bedisposed in a generally aligned flat condition, each of said side wallshaving a cover lid at its upper end, said cover lids being disposedgenerally toward each other to create a top for said basket, and saidcover lids being spaced from each other to leave an air gap forpermitting hot air to escape out of the top of said basket.
 16. A methodof baking a food item comprising providing an oven having a housing witha heating zone in the interior of the housing and with an unheatedwaiting zone at the top of the housing, providing an open mesh bakingbasket having a pair of open mesh side walls, placing a food item in thebaking basket, placing the baking basket in the waiting zone, heatingthe heating zone by vertically oriented heater elements in the heatingzone and by at least one longitudinally disposed elongated heater memberat the bottom of the heating zone, maintaining the baking basket in thewaiting zone until a predetermined temperature is reached in the heatingzone, lowering the baking basket into the heating zone when thepredetermined temperature is reached with the vertically orientedheating elements located juxtaposed the vertical mesh sides of thebaking basket and with the elongated heater member located below thebaking basket, removing the baking basket from the heating zone afterthe food item has been baked, and then removing the food item from thebaking basket.